1. Field of the Invention
The present invention relates to a method for restoring underwater pilings such as concrete, wood and steel pilings, and other underwater structures and to an underwater injection jacket specifically designed for use with and for carrying out the method.
2. Description of the Prior Art
Heretofore various techniques have been provided for forming an encasement or jacket around a deteriorated underwater piling with a worn or corroded surface and/or with cracks therein. Such techniques have typically involved forming a concrete jacket around the piling. Examples of such prior art method and apparatus for encasing an existing underwater piling in a concrete jacket are disclosed in the following U.S. patents:
______________________________________ U.S. PAT. NO. PATENTEE ______________________________________ 518,354 Polhamus 1,025,112 Davis 2,412,185 Weber ______________________________________
Also it has been proposed to establish a jacket of asphalt around a concrete piling in the Osborne U.S. Pat. No. 1,814,332.
More recently it has been proposed in the Shaw, et al. U.S. Pat. No. 3,719,049 to provide a splash zone corrosion proofing means comprising a flexible membrane made of synthetic rubber, neoprene, chlorosulfonated polyethylene, etc. which is fitted around a portion of a piling to be protected and then closed with a slide fastener such as a zipper fastening means. Once the membrane has been mounted in place, a cavity is defined between the membrane and the piling and this cavity is then filled with an inhibitor such as a petroleum base hydrophobic cationic rust-inhibiting material.
Still further, it has been proposed to provide in the Wiswell, Jr. U.S. Pat. No. 3,553,970 an inflatable clamping device around a piling for applying a a plastic or epoxy resin to the piling. This patent discloses an inflatable device made of a fluid-impervious flexible inflatable material into which is inserted a plastic or resin, and preferably an epoxy resin, which is mixed with a curing agent. This patent teaches a means for maintaining a desired temperature and pressure within the inflatable device to ensure proper curing of the plastic or resin composition therein.
As will be described in greater detail hereinafter, the underwater injection jacket of the present invention differs from the inflatable clamping device disclosed in the Wiswell, Jr. patent by providing a sheet of flexible but stiff material which is coiable into a jacket that can be of any desired size around a portion of a piling of any size and which has simple means for drawing the margins of the mating edges of the sheet toward one another to provide a tight jacket around the piling with a closed annular space formed between the piling and the jacket.
Also as will be described in greater detail hereinafter, the method of the present invention differs from the method disclosed in the Wiswell Jr. patent by providing a method for the injection of an epoxy resin composition without maintaining a special pressure or temperature on the epoxy resin composition and for injecting a special epoxy resin composition, and for not only filling the annular space formed within the jacket but also for drawing epoxy resin into the cracks in the piling such as cracks in a concrete piling. The special epoxy resin composition utilized in the method of the present invention cures, sets and bonds to wet substrates at temperatures as low as 33.degree. F. and to dry substrates at temperatures as low as 0.degree. F.
Other differences between applicant's method and underwater injection jacket utilized in practicing such method will be apparent from the detailed description of the invention set forth in greater detail below.